Are the color swatches in Blender linearized?
You shouldn't need to, no. The RGB values (that is, the actual numbers) in the RGB tab of the picker are linear, but the displayed swatch is a display-space version of that input. The HSV and hex-code tabs of the color picker are also converted to display space, so you can use those if you need to input a specific display-space color.

So if you're expecting stuff like in older versions of Maya where you have to fix the swatch, that's not necessary. What you see in the swatch is what you get in the end. Do keep in mind the RGB value tab is already linear though, that can throw off some people used to other software where you type in display-space values and they are converted at render time.